Letter: L
- l2tpd - Layer 2 Tunnelling Protocol Daemon (RFC 2661)
- lablgl - LablGL is an OpenGL interface for Objective Caml
- lablgtk - Objective Caml interface to gtk+
- ladspa - LADSPA SDK, example plug-ins and tools
- lagan - Local, global, and multiple alignment of DNA sequences
- lapack - The LAPACK libraries for numerical linear algebra.
- lash - LASH Audio Session Handler
- lasi - C++ library for creating Postscript documents
- lcdf-typetools - Tools for manipulating Postscript fonts
- lcms - Color Management System
- lcov - LTP GCOV extension code coverage tool
- leafnode - Leaf site offline NNTP server
- leafpad - GTK+ based simple text editor
- lft - Alternate traceroute tool
- lib3ds - 3D Studio file format library
- lib765 - A library for emulating the uPD765a floppy controller
- libAfterImage - A generic image manipulation library
- libannodex - Library for annotating and indexing networked media
- libapreq2 - Apache HTTP request library
- libassuan - GnuPG IPC library
- libbinio - A software library for binary I/O classes in C++
- libcaca - Library for Colour AsCii Art, text mode graphics
- libcddb - Library (C API) for accessing CDDB servers
- libcdio - CD-ROM input and control library
- libchewing - Intelligent phonetic input method library for Traditional Chinese
- libchmxx - C++ bindings for chmlib
- libcmml - Library for handling Continuous Media Markup Language
- libdaemon - Lightweight C library that eases the writing of UNIX daemons
- libdap - The C++ DAP2 library from OPeNDAP
- libdnet - Simple portable interface to lowlevel networking routines
- libdsk - Library for accessing disk images
- libeXosip2 - A library that hides the complexity of using the SIP protocol
- libebml - Extensible Binary Meta Language library
- libedit - The NetBSD Editline library (libedit)
- libesmtp - SMTP client library
- libetpan - Portable, efficient middleware for different kinds of mail access
- libevent - Abstract asynchronous event notification library
- libfac - Extension to Singular-factory
- libfwbuilder - Firewall Builder API
- libgda - Library for writing gnome database programs
- libgdamm - C++ wrappers for libgda
- libglademm24 - C++ wrapper for libglade
- libgnomecanvasmm26 - C++ interface for Gnome libs (a GUI library for X)
- libgnomedb - Library for writing gnome database programs
- libgnomemm26 - C++ interface for Gnome libs (a GUI library for X)
- libgnomeuimm26 - C++ interface for Gnome libs (a GUI library for X)
- libibverbs - A library for direct userspace use of InfiniBand
- libid3tag - ID3 tag manipulation library
- libifp - A general-purpose library-driver for iRiver's iFP portable audio players
- libkexif - Allow Kipi plugins to extract EXIF information
- libkipi - Common plugin infrastructure for KDE image applications
- libksba - X.509 library
- liblo - Open Sound Control library
- liblrdf - Library for manipulating RDF files describing LADSPA plugins
- libmal - A convenience library for malsync
- libmatroska - Open audio/video container format library
- libmcrypt - Encryption algorithms library
- libmodplug - Modplug mod music file format library
- libmpcdec - Musepack audio decoding library
- libmthca - Mellanox InfiniBand HCA Userspace Driver
- libnasl - Nessus Attack Scripting Language
- libnc-dap - The NetCDF interface to DAP-2 from OPeNDAP
- libnet - C library for portable packet creation and injection
- libnet10 - High-level API (toolkit) to construct and inject network packets
- libnetfilter_conntrack - Netfilter conntrack userspace library
- libnfnetlink - Netfilter netlink userspace library
- libnjb - A software library for talking to the Creative Nomad Jukeboxes and Dell DJs
- liboggz - Simple programming interface for Ogg files and streams
- liboil - Library of Optimized Inner Loops, CPU optimized functions
- libol - Support library for syslog-ng
- libopensync - A synchronization framework
- libopensync-plugin-evolution2 - Evolution 2 plugin for libopensync
- libopensync-plugin-file - File plugin for libopensync
- libopensync-plugin-gpe - GPE plugin for libopensync
- libopensync-plugin-irmc - Irmc plugin for libopensync
- libopensync-plugin-kdepim - KDE plugin for libopensync
- libopensync-plugin-palm - Palm plugin for libopensync
- libopensync-plugin-python - Python plugin for libopensync
- libosip - oSIP is an implementation of SIP
- libosip2 - oSIP is an implementation of SIP
- libotr - Off-The-Record Messaging library and toolkit
- libpolyxmass - Polymer chemistry-related functionalities
- libpqxx - C++ client API for PostgreSQL
- libqalculate - Multi-purpose calculator library
- librsync - Rsync libraries
- librx - POSIX regexp functions
- libsamplerate - Sample rate conversion library for audio data
- libsexy - Funky fresh graphical widgets for GTK+ 2
- libshout - icecast source streaming library
- libsidplay - Commodore 64 music player and SID chip emulator library
- libsigc++ - Typesafe signal framework for C++
- libsigc++20 - Typesafe signal framework for C++
- libsigsegv - Library for handling page faults in user mode
- libsndfile - Library for reading and writing sound files
- libspectrum - A library for reading spectrum emulator file formats
- libstatgrab - Make system statistics
- libsx - Simple X library
- libtabe - Chinese lexicons library for xcin-2.5.3
- libtar - Tar file manipulation API
- libtasn1 - This is the ASN.1 library used in GNUTLS
- libtlen - Tlen.pl client library
- libtomoe-gtk - Gtk library for tomoe Japanese handwritten input
- libtorrent - BitTorrent library with a focus on high performance & good code
- libtranslate - Natural language translation library
- libtunepimp - A library for creating MusicBrainz enabled tagging applications
- libuninameslist - Library that provides Unicode names and annotations
- libupnp - Universal Plug and Play (UPnP) SDK
- libvisual - Abstraction library for audio visualisation plugins
- libvisual-plugins - Plugins for use with libvisual
- libxfce4mcs - Multi-channel settings management support for Xfce
- libxfce4util - Utility library for the Xfce4 desktop environment
- libxfcegui4 - GTK widgets for Xfce
- libxml++ - C++ wrapper for the libxml2 XML parser library
- libzvt - Zed's Virtual Terminal library
- licq - Licq - A graphical ICQ Client for Linux
- liferea - An RSS/RDF feed reader
- lightning - GNU Lightning
- lighttpd - Lightning fast webserver with light system requirements
- lincity-ng - City Simulation Game
- lincvs - Graphical CVS Client
- link-grammar - A Grammar Checking library
- linphone - Phone anywhere in the whole world by using the Internet
- linux_logo - The linux logo - a colorful console penguin logo
- lirc - The Linux Infrared Remote Control package
- lmarbles - Atomix clone where you create figures out of marbles
- lock-keys-applet - A GNOME panel applet that shows the status of the lock keys
- logjam - GTK2 client for LiveJournal
- loudmouth - Loudmouth is a Jabber programming library written in C
- lout - A document formatting system
- lrmi - Library for calling real mode BIOS routines
- ltsp-utils - Linux Terminal Server Project (ltsp.org) utilities
- lua - Powerful light-weight programming language
- lucidlife - A Conway's Life simulator
- lvcool - Utility to cool down Athlon CPUs when idle on Via KT133 or KX133 chipsets
- lyx - WYSIWYM (What You See Is What You Mean) document processor
- lzo - Data compression library with very fast (de)compression
- lzop - Real-time file compressor